Many states have now passed laws requiring the periodic monitoring of all underground storage tanks to assure that leakages are not a source of ground water contamination. Federal agencies are also requiring similar regulations. This monitoring is best performed in the field using portable instrumentation. Sample wells are drilled in the vicinity of underground storage tanks, and ground water from the sampling wells is analyzed to determine if contaminates arising from leaking storage tanks is present. In cases where the sampling wells are dry, soil samples are analyzed to determine if contaminates are present.
Procedures are available for the field sampling, extraction and analysis of water samples taken from sampling wells. However, efficient procedures are not available for the extraction of soil samples in the field.
The current and proposed regulations requiring monitoring of underground storage tanks have created a need for a simple, rapid, sensitive, field-usable device for determining hydrocarbons in soil samples. Portable gas chromatographs are available for determining hydrocarbons once the hydrocarbons are isolated from a soil sample. However, no satisfactory field-usable means exist for isolating hydrocarbons from solid samples. Headspace and purge and trap procedures are effective in laboratory environments for the isolation of gasoline from soil samples, but they are not usable in field situations by non-technically trained personnel. Solvent extraction procedures are also effective in laboratory situations for isolating gasoline, diesel fuel, fuel, oil and other hydrocarbons from soil samples, but they are far too complex for field use. In addition, the presently available sampling procedures do not provide the required detection limits unless very large soil samples are taken. This may pose a problem when samples are isolated from narrow bore monitoring wells.
It is therefore the principal object of this invention to provide a method and means for testing soil samples that can quickly and easily be conducted in the field by non-technical persons.
It is a further object of this invention to provide a method and means for testing soil samples which will yield a sample of hydrocarbons from a small soil sample for subsequent gas chromatographic analysis.
A further object of this invention is to provide a method and means for testing soil samples that will be completely portable and which will require no supporting utilities. (Conventional procedures do require cooling water, electricity, and pressurized gases.)
A further object of this invention is to provide a method and means for testing soil samples that is economical.
These and other objects will be apparent to those skilled in the art.